Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

AliExpress AD1865 R2R DAC
AliExpress AD1865 R2R DAC
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old Yesterday, 12:50 PM   #71
erin is offline erin  Australia
diyAudio Member
 
Join Date: Nov 2006
Location: http://www.acmuller.net/con-dao/daodejing.html
@abraxalito nice work. I like the thin wire. Almost tonearm guage?
  Reply With Quote
Old Yesterday, 12:54 PM   #72
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
I never twiddled with tonearm wires when I owned a turntable, so I dunno. Its 32AWG wire-wrap wire.

Thanks
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old Yesterday, 03:39 PM   #73
Rick Miller is offline Rick Miller  United States
diyAudio Member
 
Rick Miller's Avatar
 
Join Date: Jun 2008
Location: Sarasota, FL
Quote:
Originally Posted by Hugh Jazz View Post
That sounds good, given the filter is very close to the DAC IC so there is a short return path for the HF. What values did you use for your filter? Have you tried a very small series R, a shunt C, then another small series R?

Basically, I think a circuit tailored to the op amp/DAC IC with excellent layout and power is the best I/V solution but I've never seen anyone build a range of circuits and test each of them. It's all rather subjective without this.
I use a cap of around 330pf then a single layer 10uh choke with a DCR of 1 ohm. I have not used the RCR you describe as I like the 12db/oct of the CL filter. The most important thing is to roll off the high frequency out of band energy of the DAC chip before it goes into the I/V op-amp.
  Reply With Quote
Old Today, 12:55 AM   #74
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
Thanks. I've seen a few people post about using a similar sized cap across the differential outputs for current out DACS with great (subjective) success. Apparently it doesn't seem to have much effect with voltage out DACs like AKM. I have an ES9038 I plan to try it with but so far haven't got round to it - if it ain't broke, why hack it thing.
  Reply With Quote
Old Today, 01:10 AM   #75
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
I agree @Rick its very important to roll-off the HF before it gets to the I/V. Here's the filter I'm using with my AD8067 I/V stage - its a 3rd order LPF with enough peaking to provide NOS droop correction.

The 13ohm resistor (R3) is the termination for the filter and its value is fairly critical to getting the correct FR. With opamp I/V the input impedance at the -ve pin of the opamp is normally very low (created by feedback) so the filter can be used as-is with an opamp following. It can also be used with a discrete stage with the proviso that R3 will need to be reduced so that the sum of it with the input impedance of the I/V stage equals 13ohm.

The caps should ideally be NP0/C0G - use 4*100n in parallel for 400n and 2*100n + 2*33nF for 266n. The inductor isn't too critical in terms of ESR, I'm using SLF7045T-151 (TDK).
Attached Images
File Type: png NOS-droop-correcter.png (4.3 KB, 70 views)
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old Today, 03:44 PM   #76
Rick Miller is offline Rick Miller  United States
diyAudio Member
 
Rick Miller's Avatar
 
Join Date: Jun 2008
Location: Sarasota, FL
Abraxalito, I like your choice of I/V op-amp, FET input and high speed. I also like your LPF for the input of the I/V stage. I too have noticed the slight roll off of treble and have tried other things to bring up the highs but would like more and this filter might do the trick. I am using a TDA 1541 DAC and I know they don't like to see much voltage on their outputs. Maybe the 13 ohm would be ok, but I like to keep the voltage low at the output of the DAC.
Thanks for posting the filter.
  Reply With Quote

Reply


AliExpress AD1865 R2R DACHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
mono tpa3116 red aliexpress basreflex Class D 6 5th March 2017 05:56 PM
Transistor tester from Aliexpress ashok Equipment & Tools 8 30th May 2016 09:09 AM
Aliexpress EddieT The Lounge 9 26th November 2015 05:18 PM
about the Aurum Cantus G1 from aliexpress juanito Multi-Way 0 13th July 2013 05:28 PM
aliexpress class d amp telefunken Class D 9 26th October 2010 01:01 PM


New To Site? Need Help?

All times are GMT. The time now is 11:44 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki